This invention relates to a vacuum pump with a bearing assembly and more particularly to the vacuum pump with a magnetic bearing system of the kind having back-up bearings contained inside the shaft of the vacuum pump. This mechanical bearings set up is disclosed in the U.S. patent application No. 08/858,230 filed by Varian Associates, Inc.
The U.S. Pat. No. 5,238,362 issued Aug. 24, 1993 to Casaro, et al. discloses a turbomolecular vacuum pump for which a system according to this invention can be suitable and is assigned to the assignee herein. This patent will be incorporated herein by reference, detailed accounts of some of common components of a vacuum pump being thus omitted.
Although a vacuum pump according to aforementioned U.S. Pat. No. 5,238,362 provides increased compression ratios, it is desirable to keep improving the quality of such a vacuum pump, for example, by providing an improved bearing assembly with improved capability in radial and axial position sensing and a reduced size.